Donut-sized rock suddenly appears in front of Mars rover

As we’ve learned from our recent explorations of Mars, there’s really not a whole lot going on there. Yes, there are geological process at work, but most of them move at a nearly imperceptible pace. So that’s why after nearly ten years of Martian rover exploration, NASA scientists were surprised to see a rock suddenly “appear” in front of the Mars Rover last week.

You can see the rock in the images above. The image on the left shows the area in front of Opportunity on Sol 3528. The image to the right was taken 12 Martian days later and is almost identical—except for a rock the size of a donut that had suddenly appeared.

NASA announced the discovery of the rock at an event at Caltech in Pasadena this past Thursday night, dubbing the rock “Pinnacle Island.” “It’s about the size of a jelly doughnut,” NASA Mars Exploration Rover lead scientist Steve Squyres told Discovery News. “It was a total surprise, we were like ‘wait a second, that wasn’t there before, it can’t be right. Oh my god! It wasn’t there before!’ We were absolutely startled.”